Efforts to save Indian national Sarabjit Singh from the gallows received a boost on Monday with former premier Nawaz Sharif asking the Pakistan government not to hang him on humanitarian grounds.

The Pakistan Muslim League-Nawaz chief, whose party is a key player in the ruling coalition led by the Pakistan People's Party, however, did not favour an unconditional pardon for Sarabjit, sentenced to death for his alleged involvement in bomb attacks that killed 14 people in 1990.

"Sarabjit should be released on the condition that he would be sent back to Pakistan if concrete evidence is found against him," Sharif was quoted as saying by TV news channels.

In an interview with the Aaj news channel, Sharif also suggested that any review of Sarabjit's case by the Pakistan government should be linked to similar action by the Indian government in the cases of Pakistanis currently being held in the neighbouring country.

"After seeing the plight of the members of Sarabjit's family who have come to Pakistan, any person can feel the pain they are going through," Sharif said.

"But if this individual (Sarabjit) has actually carried out terrorist attacks, then no person can easily ignore that".

Sharif further said in the interview, "If the Pakistan government is to examine this matter, then the issue of Pakistanis being held in India for similar cases should be linked to it".

The other TV channels said Sharif hinted that Sarabjit could be swapped for Pakistanis currently being held in Indian jails.

Sharif's comments came even as authorities in Punjab province put off Sarabjit's hanging for up to three weeks.

Sarabjit was originally set to be hanged on April 1, but his execution was deferred for 30 days by President Pervez Musharraf [Images]. This was done so that Pakistan's new government could review his case following an appeal for clemency from the Indian government.

According to existing rules, Sarabjit's case has to be put up again before a local court for fixing a fresh date for the execution.

The fresh date cannot be fixed before a period of 14 days or after 21 days. This means that the execution will be postponed for up to three weeks, officials said.

"It's a very good sign," Burney told PTI, adding he was ready to share the evidence he had gathered in Sarabjit's case with Sharif.

"Due to the suspicious nature of the case against Sarabjit, his execution should not be carried out. Relations between India and Pakistan are improving and India's External Affairs Minister Pranab Mukherjee is scheduled to visit Pakistan next month. In view of these developments, the government should review Sarabjit's case," he said.

Burney also said he had sought appointments with Musharraf and Prime Minister Yousuf Raza Gillani to take up Sarabjit's case and was hopeful of meeting them sometime soon.